1. Technical Field
This invention relates to a two frame collapsible chair which can be folded into a transport configuration.
2. Description of Related Art
When participating in activities such as fishing, hunting, and attending sporting events such as youth soccer or baseball, it is desirable to have a portable folding chair that is easy to carry. In addition, it is desirable or necessary to carry other items such as drinks, food, sunscreen and other various sundries.
Folding chairs currently on the market and commonly used tend to be heavy and cumbersome to carry and many fold up and must be placed into a bag for carrying. Others that fold the seat to the back tend to unfold while in transport and their size and weight make them difficult for adults short in stature or children to carry. Further, carrying other items or tending to small children or pets is difficult with only one available arm.
Many people choose to wear a backpack to carry the various items needed for the activity and then carry their chair in one hand. Again, the difficulties mentioned previously still exist and when arriving at their destination, the user now has two separate items to care for.
Several examples of prior art exist to address the idea of carrying a fold up chair on one's back in combination with a backpack. However, such prior art tends to be heavy, cumbersome and unstable when unfolded. In addition, the prior art is large when folded which increases shipping costs to retailers and takes up valuable retail shelf space as well as storage space for the end user. An example of such a product is disclosed in Amman U.S. Pat. No. 6,547,324B1, hereinafter “Amman”, which discloses a three frame chair having the backpack portion mounted on the backrest. The Amman chair suffers from several disadvantages. First, no provision exists for holding the backrest in the upright position when no one is sitting in the chair. If the chair is sitting on an un-level surface, which will be common in its intended use, the backrest will fall over onto the seat when the user stands up. Second, the lower frame does not extend below the center of gravity of the backpack itself. If the backpack has much weight in it, the chair will tip over backwards when first opened or when the user stands up. Third, no provision exists to adjust the angle of the backrest without also affecting the seat height. The backrest can be adjusted but the action requires that the seat height be lowered disproportionately. Further, the structure requires the use of three frames that do not fold into the same plane, which takes up more space and presents storage and shipping problems as noted above. As those skilled in the art will appreciate, an additional frame adds to the cost of manufacturing both in labor and raw materials required. Consequently, it is desirable to have a chair which can be manufactured with decreased raw material and labor costs.
Additionally with the chair in Amman, when in the folded position and carried on one's back, the frames are in direct contact with the user's back and the weight of the chair and backpack load are concentrated in small areas of the user's back. While foam padding can be employed on the frame, such padding does not distribute the load satisfactorily, especially when the backpack is heavy and/or when traveling significant distances. Another disadvantage is that the armrests require vertical structural members attached to both of the chair frames. As discussed above, this adds to the overall weight and manufacturing costs and also reduces long term reliability. Finally, a strap and buckle arrangement is employed to hold the chair in the folded position for wearing on one's back. Because the shoulder straps are attached to the bottom of the seat frame, the chair would unfold while in use if the strap and buckle arrangement were to fail. These are just a few of the problems with the chair disclosed by Amman. These illustrate many of the inherent design problems which are common with other known prior art chairs. These problems limit the use and comfort of the chair, add to the weight and bulk of the chair, increase the raw material and manufacturing costs of the chair, and lead to an overall dissatisfactory solution to a common problem. Consequently, it is desirable to have a chair which is less expensive to manufacture, which is easier to carry, which has the “extras” such as a backrest and armrests, and which is more enjoyable to use.